Thread checker



oct. 22, 1946.`

R. E. BAUER THREAD CHECKER `Fild Nov. 1o, 1944 Oct. 22, 1946. R' BAUER 2,409,924

v THREAD GHEGKER Filed Nov. 10 1,944 3 Sheets-Sheet 2 errbmwsyo:

C 22,. 1946. l R, E, BAUER 2,409,924

THREAD CHECKE Filed Nov. 10( 1944' 3 Sheets-Sheet 5 INVENTR. )zfseZZZZdlle H fr0/7 Era.

rammed oct. 22, 1946 UNITED STATES PATENT oFEicE 2,409,924 THREAD cHEoKER.

Russell E. Bauer, Detroit, Mich.

Application November 10, 1944, Serial No. 562,752

thread, and while the lead may check by measurement along one side of the threaded workpiece in a certain plane, in a plane opposite thereto or on the opposite sides of the workpiece in the same plane the thread may be off from the true helix.

Other objects of the invention will become ap parent from the following specication, the

drawings relating thereto, and from the claims hereinafter set forth.

In the drawings, in which like numerals designate like parts in the several views throughout:

l, Figure l is a top plan view of the thread checking and Ymeasuring device embodying features of the present invention; I

Fig. 2 is a view taken in the direction of the arrow 2 of Fig. 1, with parts removed and showing parts in cross-section thereof;

.. i Fig. 3 is an end elevational view taken in the direction of the arrow 3 of Fig. 1 and with one of the centering means removed;

Fig. 4 is a cross-sectional View taken substantially along the line 4 4 of Fig. 1; and

Fig. 5 is a fragmentary end view taken from the left end of Fig. 2.

Referring to the drawings, the thread measuring and checking device comprises a base I having a workpiece carrying and supporting member 2 mounted thereon. The supporting member 2 is Vmounted for longitudinal translation and transverse tilting movement with respect to the base. In `order to so mount the member 2 the upper surface of the base is formed with a longitudinally extending raceway 3, which is generally V-shaped in section. The underside of member relation so that the member 2 may roll longitudinally of the raceway 3 and may tilt transversely thereof in either direction. Suitable stops may be provided on the raceways to limit the movement of the b-alls and to retain them in properly spaced relation.

A workpiece 6, which is a screw-threaded element, is supported on the member 2 and is centered thereon by means of a pair of facing centers AIl andi.` The centers 'I and 8 have facing (c1. as me) and pointed ends which arevadapted to be received within centered recesses formed in the ends of the workpiece 6 so that the workpiece 6 is properly centered on the mounting member 2 5 with the axis of the workpiece extending parallel to the axis of raceways 3 and 4.

The member 2 is generally U-shaped and has upwardly extending arms 9 and I0, upon which the centers 'l and 8 are mounted, respectively. The upper surfaces of the arms are for-med with T-slots II which receive the heads of screws I2 therein. The screws extend upwardly through the centers 'i and 3 and have thumb nuts I3 threaded to the upper ends thereof so that the centers l and 8 may be xed in their longitudinal positions on arms 9 and I. One of the centers, such as l, is hollow and has a compression spring I4 disposed therein, one end of which abuts against the inner surface of the center 1 and the opposite end of which abuts against a block I5 which is also received within the hollow center l. 'Ihe shank of the screw I2 extends through the block I5 and through elongated openings I6 formed in the center l so that the center 'I may may be resiliently urged toward the workpiece. Clamping member I'I is disposed under the thumby screw I3 and engages the upper surface of the center] so that such center may be frictionally held in its longitudinal position.

A pair of oppositely disposed thread contacting members I8 and I9 are mounted on the base l and are positioned to engage the thread of the workpiece on opposite sides thereof. The members I 8 and I9 have pointed ends which engage in the thread. The contact member I8 is mounted on an upstanding bracket 29 which may be fixed to one side of the base I. The member I8 is received through an aperture 2l formed in the member and may be adjustably xed therein by means of a setscrew 22.

The member I9 is relatively long and is mov` ably mounted on the top surface of a carrier or slide 23. The slide 23 is mounted for movement along the top surface of another slide 24. The slide 24 is mounted for longitudinal movement `along the base I. The upper surface of base I is formed with trackways 25, which slidably support the carriage 24 thereon for movement parallel to raceway 3. Carriage 23 may be fixed in any of its longitudinal positions by means of a bolt 26 having a laterally offset head 2T which is received within a longitudinally extending angular recess 28. The bolt 26 extends through the carriage 24 andthe threaded upper end thereof is threadably received within the threaded shank of a thumb nut 29. By tightening the thumbnut it will be seen that the adjacent surfaces of the head 21 and recess 28 are pulled together so that the carriage 24 is xed in position. The carriage 23 is slidably mounted on the top surface of carriage 24 for movement toward and from the axis of the workpiece, or in a direction transverse to the direction of movement of carriage 24. To somount the carriage 23 the upper surfacerof carriage 24 is formed `with trackways 39 upon which the undersurface of carriage 23 slides. A recess 3 similar to recess 28, is formed in the top surface of member 24 and receives the offset head 32 of a screw 33 whichextends upwardly through carriage 23 at an angle. A thumb nut 34 is threaded to the threaded end of screw 33, and the carriage 23 may lbe vadjusted along the length of recess 3| with respect to carriage 24.

The contact member I9, which is in the form of an elongated rod, is mounted on the top? surface of lcarriage 23 for pivotal movement about its end indicated at 35. Suchend 35 has a center recess formed therein into which the pointed end of a centering screw is received. The centering screw 36 may be threaded into a tapped opening in an upwardly projecting end 31 of the carriage A23. The Contact member I9 is supported above the top surface of the carriage 23 by means of a supporting member 38 which is slidably received on the top surface of carriage 23. The member 38 may be moved along the contact I9 to its proper position and may be fixed in position by means of a setscrew which extends through the top thereof and engages the contact |9. The lateral movement of the contact I9 is limited by upwardly projecting stop pins and 6 |V which are mounted on the top surface of slide 23 adjacent the pointed end of contact I9.

A conventional dial indicator iiD, having the conventional plunger 4|, is mounted on carriage 23 by means of a rigid bracket 42. On end of the bracket 42 is fixed ,to the carriage 23, and the opposite end is xed to a depending luglli which may be fixed to the dial indicator casing. As mentioned, the dial indicator 'lill is of conventional construction and has the conventional pointer which is actuated through a spring ratchet by the Aplunger 4 The plunger M'bears against the adjacent side of contact I 9. Contact I9 is resiliently urged into contact with Vthe plunger 4| by means of a coil spring 45. One end of `the coil spring 45 isconnected toa pin 46 which in turn is fixed to the projection 3l; andthe opposite end of the spring '115 is fixed to a pin 41 which is xed to the collar 3.8.

To check the drunkenness of the thread of a workpiece B, the device is set up so that contacts i8 and I9 engage in the thread on opposite sides thereof. The base is preferably tilted by placing ,a shim under the right-hand end `(viewing Fig.' 2) so that the carriage or supporting member 2 .tendsto roll 'toward the lef-t. This insures the threads will bear against the points at all times during the operation. By then rotating the workpiece 5 so that the carriage 2 runs along its raceways any deviation in the thread from the true helix will .eiect a lateral displacement of contact i9. The deflection of contact "I9 will cause plunger il to move and indicate the extent of deflection on the dial indicator 49.

. To check the lead of the thread, the contact it `is removed and the workpiece is positioned .against .contact |19 .so that itleans thereagainst. .A stop 5|] in the form .of a`bar of the same diameter as the balls V5is .mounted in the trackway .3 for adjustment therealong adjacent one end of theraceway .3. .'I'he stopy 5D, has a diametric projection 53 along one end, and the carriage'2 is fi then moved so that the face of a stop 5| mounted ,thereon abuts against the projection of the stop 56. The stop 59 is held in adjusted position by a clamp 5d which has a V-groove on the undersurface thereof engageable with the top surface of stop 59. The clamp 54 is mounted on the base by means of a screw 55. The carriage 2 is then positioned so that the thread is engaged by the pointed end of contact I9. The rim of the dial may lthen be turned so that the pointer is at zero. If it is then desired to check the lead for a particular length therealong a gage block 52 of that particular dimension is disposed betweenl the faces of stops and 5| with such faces engaging the opposite ends of the gage block. The thread is then brought into engagement with Contact |9,

Aand any variation in the lead will then be yindicated by a deflection of the pointer 9 which will depress plunger 4| to move the pointer of the dial indicator itil. Formal changes may be made inthe specific embodiment of the invention described without departing from the-invention, lthe scope of which is commensurate with theappended claims.

What is claimed is:

l. A device for measuring and checking threaded workpieces comprising a base, a workpiece supporting member, center mounting members on said supporting member and adapted to mount a centered workpiece therebetween, means mounting said supporting member on said base for movement along and tilting movement transversely to the longitudinal axis of said workpiece, said last-named means including facing racelways formed on-said supporting member and said base with ball members interposed therebetween, thread contact means mounted on said base and positioned to engage the thread of the workpiece, said contact means including an element having an end positioned to engage said .'thread, means movably mounting said element,

cator means mounted on said base and actuated `by movement of said one of said contact members.

3. A ,device for Y -measuring and checking threaded workpieces comprising a base, a workpiece supporting member, center mounting members on saidsupporting member and adapted to kmou-nt a centered workpiece therebetween, means mounting said supporting member on said base for movement along andV tiltingmovement transversely -tothe longitudinal axis of said workpiece, said last-named means including facing raceways formedy on said supporting member and said base with ballfmembersinterposed therebetween, a pair of oppositely disposed threadcontact members mounted on said base and positioned to engage the thread of the workpiece, means movably mounting one of said contact members, ,and indicator means ,mounted on said base and actuated by movement of said one of said contactmembers.

' RUSSELL E. BAUER. 

